This guy implanted an RFID chip in his hand.
"Well, the RFID chip is finally in. Now it's time to get on with buying a house that I can deck out with RFID sensors. But, probably before I get a chance to do that, I'm going to put a sensor in my car door. One small step for hand, one giant leap for keyless entry. Another thing I'm going to work on is figuring out how to write a custom GINA for Windows and putting a sensor into my keyboard so when I place my hands on it, the system will automatically log me in."